BODY (SOMATIC) CELL 



Maternal chromosomes 

 PRIMORDIAL GERM CELL 

 Paternal chromosomes 



OOGONIUM 



INDIVIDUAL 



OOGONIUM 



Homologous chromosomes in synapsis 

 PRIMARY OOCYTE 



TWO CELLED EMBRYO 

 I 



Tetrad 



PRIMARY OOCYTE 



End view of tetrad 



SECONDARY OOCYTE 



MATURE EGG 



First maturation 

 (reduction) division 

 1^ 



Second maturation 

 (equation) division 



/ 1^ 



' I 



FIRST POLAR 

 BODY 





SECOND POLAR BODY 



were in the mature gametes. In the interest of simphcity, the 23 pairs of chromosomes m man 

 are represented here by only two pairs; however, the principle of maturation is exactly the same 

 for two pairs of chromosomes as for 100 pairs. These diagrams illustrate well the continuity ot 

 chromosomes. 



577 



